/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#ifndef http_parser_h
#define http_parser_h
#ifdef __cplusplus
extern "C"
{
#endif

    /* Also update SONAME in the Makefile whenever you change these. */
#define HTTP_PARSER_VERSION_MAJOR 2
#define HTTP_PARSER_VERSION_MINOR 1
#define HTTP_PARSER_VERSION_PATCH 0

#include <sys/types.h>
#if defined(_WIN32) && !defined(__MINGW32__) && (!defined(_MSC_VER) || _MSC_VER<1600)
#include <BaseTsd.h>
#include <stddef.h>
    typedef __int8 int8_t;
    typedef unsigned __int8 uint8_t;
    typedef __int16 int16_t;
    typedef unsigned __int16 uint16_t;
    typedef __int32 int32_t;
    typedef unsigned __int32 uint32_t;
    typedef __int64 int64_t;
    typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif

    /* Compile with -DHTTP_PARSER_STRICT=0 to make less checks, but run
     * faster
     */
#ifndef HTTP_PARSER_STRICT
# define HTTP_PARSER_STRICT 1
#endif

    /* Maximium header size allowed */
#define HTTP_MAX_HEADER_SIZE (80*1024)

    typedef struct http_parser http_parser;
    typedef struct http_parser_settings http_parser_settings;

    /* Callbacks should return non-zero to indicate an error. The parser will
     * then halt execution.
     *
     * The one exception is on_headers_complete. In a HTTP_RESPONSE parser
     * returning '1' from on_headers_complete will tell the parser that it
     * should not expect a body. This is used when receiving a response to a
     * HEAD request which may contain 'Content-Length' or 'Transfer-Encoding:
     * chunked' headers that indicate the presence of a body.
     *
     * http_data_cb does not return data chunks. It will be call arbitrarally
     * many times for each string. E.G. you might get 10 callbacks for "on_url"
     * each providing just a few characters more data.
     */
    typedef int (*http_data_cb)(http_parser*, const char *at, size_t length, void* obj);
    typedef int (*http_cb)(http_parser*, void* obj);

    /* Request Methods */
#define HTTP_METHOD_MAP(XX)         \
    XX(0,  DELETE,      DELETE)       \
    XX(1,  GET,         GET)          \
    XX(2,  HEAD,        HEAD)         \
    XX(3,  POST,        POST)         \
    XX(4,  PUT,         PUT)          \
    /* pathological */                \
    XX(5,  CONNECT,     CONNECT)      \
    XX(6,  OPTIONS,     OPTIONS)      \
    XX(7,  TRACE,       TRACE)        \
    /* webdav */                      \
    XX(8,  COPY,        COPY)         \
    XX(9,  LOCK,        LOCK)         \
    XX(10, MKCOL,       MKCOL)        \
    XX(11, MOVE,        MOVE)         \
    XX(12, PROPFIND,    PROPFIND)     \
    XX(13, PROPPATCH,   PROPPATCH)    \
    XX(14, SEARCH,      SEARCH)       \
    XX(15, UNLOCK,      UNLOCK)       \
    /* subversion */                  \
    XX(16, REPORT,      REPORT)       \
    XX(17, MKACTIVITY,  MKACTIVITY)   \
    XX(18, CHECKOUT,    CHECKOUT)     \
    XX(19, MERGE,       MERGE)        \
    /* upnp */                        \
    XX(20, MSEARCH,     M-SEARCH)     \
    XX(21, NOTIFY,      NOTIFY)       \
    XX(22, SUBSCRIBE,   SUBSCRIBE)    \
    XX(23, UNSUBSCRIBE, UNSUBSCRIBE)  \
    /* RFC-5789 */                    \
    XX(24, PATCH,       PATCH)        \
    XX(25, PURGE,       PURGE)        \

    enum http_method
    {
#define XX(num, name, string) HTTP_##name = num,
        HTTP_METHOD_MAP(XX)
#undef XX
}        ;

        enum http_parser_type
        {   HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH};

        /* Flag values for http_parser.flags field */
        enum flags
        {   F_CHUNKED = 1 << 0
            , F_CONNECTION_KEEP_ALIVE = 1 << 1
            , F_CONNECTION_CLOSE = 1 << 2
            , F_TRAILING = 1 << 3
            , F_UPGRADE = 1 << 4
            , F_SKIPBODY = 1 << 5
        };

        /* Map for errno-related constants
         * 
         * The provided argument should be a macro that takes 2 arguments.
         */
#define HTTP_ERRNO_MAP(XX)                                           \
    /* No error */                                                     \
    XX(OK, "success")                                                  \
    \
    /* Callback-related errors */                                      \
    XX(CB_message_begin, "the on_message_begin callback failed")       \
    XX(CB_status_complete, "the on_status_complete callback failed")   \
    XX(CB_url, "the on_url callback failed")                           \
    XX(CB_header_field, "the on_header_field callback failed")         \
    XX(CB_header_value, "the on_header_value callback failed")         \
    XX(CB_headers_complete, "the on_headers_complete callback failed") \
    XX(CB_body, "the on_body callback failed")                         \
    XX(CB_message_complete, "the on_message_complete callback failed") \
    \
    /* Parsing-related errors */                                       \
    XX(INVALID_EOF_STATE, "stream ended at an unexpected time")        \
    XX(HEADER_OVERFLOW,                                                \
            "too many header bytes seen; overflow detected")                \
    XX(CLOSED_CONNECTION,                                              \
            "data received after completed connection: close message")      \
    XX(INVALID_VERSION, "invalid HTTP version")                        \
    XX(INVALID_STATUS, "invalid HTTP status code")                     \
    XX(INVALID_METHOD, "invalid HTTP method")                          \
    XX(INVALID_URL, "invalid URL")                                     \
    XX(INVALID_HOST, "invalid host")                                   \
    XX(INVALID_PORT, "invalid port")                                   \
    XX(INVALID_PATH, "invalid path")                                   \
    XX(INVALID_QUERY_STRING, "invalid query string")                   \
    XX(INVALID_FRAGMENT, "invalid fragment")                           \
    XX(LF_EXPECTED, "LF character expected")                           \
    XX(INVALID_HEADER_TOKEN, "invalid character in header")            \
    XX(INVALID_CONTENT_LENGTH,                                         \
            "invalid character in content-length header")                   \
    XX(INVALID_CHUNK_SIZE,                                             \
            "invalid character in chunk size header")                       \
    XX(INVALID_CONSTANT, "invalid constant string")                    \
    XX(INVALID_INTERNAL_STATE, "encountered unexpected internal state")\
    XX(STRICT, "strict mode assertion failed")                         \
    XX(PAUSED, "parser is paused")                                     \
    XX(UNKNOWN, "an unknown error occurred")

        /* Define HPE_* values for each errno value above */
#define HTTP_ERRNO_GEN(n, s) HPE_##n,
        enum http_errno
        {
            HTTP_ERRNO_MAP(HTTP_ERRNO_GEN)
        };
#undef HTTP_ERRNO_GEN

        /* Get an http_errno value from an http_parser */
#define HTTP_PARSER_ERRNO(p)            ((enum http_errno) (p)->http_errno)

        struct http_parser
        {
            /** PRIVATE **/
            unsigned char type : 2; /* enum http_parser_type */
            unsigned char flags : 6; /* F_* values from 'flags' enum; semi-public */
            unsigned char state; /* enum state from http_parser.c */
            unsigned char header_state; /* enum header_state from http_parser.c */
            unsigned char index; /* index into current matcher */

            uint32_t nread; /* # bytes read in various scenarios */
            uint64_t content_length; /* # bytes in body (0 if no Content-Length header) */

            /** READ-ONLY **/
            unsigned short http_major;
            unsigned short http_minor;
            unsigned short status_code; /* responses only */
            unsigned char method; /* requests only */
            unsigned char http_errno : 7;

            /* 1 = Upgrade header was present and the parser has exited because of that.
             * 0 = No upgrade header present.
             * Should be checked when http_parser_execute() returns in addition to
             * error checking.
             */
            unsigned char upgrade : 1;

            /** PUBLIC **/
            void *data; /* A pointer to get hook to the "connection" or "socket" object */
        };

        struct http_parser_settings
        {
            http_cb on_message_begin;
            http_data_cb on_url;
            http_cb on_status_complete;
            http_data_cb on_header_field;
            http_data_cb on_header_value;
            http_cb on_headers_complete;
            http_data_cb on_body;
            http_cb on_message_complete;
            void* object;
        };

        enum http_parser_url_fields
        {   UF_SCHEMA = 0
            , UF_HOST = 1
            , UF_PORT = 2
            , UF_PATH = 3
            , UF_QUERY = 4
            , UF_FRAGMENT = 5
            , UF_USERINFO = 6
            , UF_MAX = 7
        };

        /* Result structure for http_parser_parse_url().
         *
         * Callers should index into field_data[] with UF_* values iff field_set
         * has the relevant (1 << UF_*) bit set. As a courtesy to clients (and
         * because we probably have padding left over), we convert any port to
         * a uint16_t.
         */
        struct http_parser_url
        {
            uint16_t field_set; /* Bitmask of (1 << UF_*) values */
            uint16_t port; /* Converted UF_PORT string */

            struct
            {
                uint16_t off; /* Offset into buffer in which field starts */
                uint16_t len; /* Length of run in buffer */
            }field_data[UF_MAX];
        };

        /* Returns the library version. Bits 16-23 contain the major version number,
         * bits 8-15 the minor version number and bits 0-7 the patch level.
         * Usage example:
         *
         *   unsigned long version = http_parser_version();
         *   unsigned major = (version >> 16) & 255;
         *   unsigned minor = (version >> 8) & 255;
         *   unsigned patch = version & 255;
         *   printf("http_parser v%u.%u.%u\n", major, minor, version);
         */
        unsigned long http_parser_version(void);

        void http_parser_init(http_parser *parser, enum http_parser_type type);

        size_t http_parser_execute(http_parser *parser,
                const http_parser_settings *settings,
                const char *data,
                size_t len);

        /* If http_should_keep_alive() in the on_headers_complete or
         * on_message_complete callback returns 0, then this should be
         * the last message on the connection.
         * If you are the server, respond with the "Connection: close" header.
         * If you are the client, close the connection.
         */
        int http_should_keep_alive(const http_parser *parser);

        /* Returns a string version of the HTTP method. */
        const char *http_method_str(enum http_method m);

        /* Return a string name of the given error */
        const char *http_errno_name(enum http_errno err);

        /* Return a string description of the given error */
        const char *http_errno_description(enum http_errno err);

        /* Parse a URL; return nonzero on failure */
        int http_parser_parse_url(const char *buf, size_t buflen,
                int is_connect,
                struct http_parser_url *u);

        /* Pause or un-pause the parser; a nonzero value pauses */
        void http_parser_pause(http_parser *parser, int paused);

        /* Checks if this is the final chunk of the body. */
        int http_body_is_final(const http_parser *parser);

#ifdef __cplusplus
    }
#endif
#endif
